An iceberg the size of lower Manhattan broke off a Greenland glacier

Researchers witnessed — and recorded — a 4-mile-wide chunk of ice calving off the Helheim glacier in late June.

Calving events, where large blocks of ice break from a glacier, happen every day. But witnessing a 4-mile-wide, half-mile-deep, and mile-plus-long iceberg dumping into the ocean is different.

That’s what happened to a team of New York University scientists posted in east Greenland on June 22. Over the span of 30 minutes, these researchers witnessed a large “tabular” iceberg calve off from the Helheim glacier, followed by smaller “pinnacle” icebergs. In total, the NYU researchers estimate that the amount of ice unloaded was about the size of lower and midtown Manhattan combined.

Luckily for scientists studying calving events, the NYU scientists also caught the event on video, which they released condensed into a 90-second clip.

While large, this break is smaller than others seen on the island. In 2010, a 100-square-mile ice sheet broke off the Petermann glacier, followed by another large break in 2012 — although the glacier has grown back a little since then. Still, scientists are keeping a close eye on Petermann and other large glaciers on Greenland as the Arctic continues to warm and these large calving events become more frequent.

“The real message here to me is not that this particular event is unprecedented, but that it’s not unprecedented: That these monster calving events are becoming more and more common as time goes on,” Tad Pfeffer, a glaciologist at the University of Colorado, Boulder told Earther.